On Tue, Mar 16, 2021 at 09:42:42PM +0100, Mickaël Salaün wrote: > From: Mickaël Salaün <mic@xxxxxxxxxxxxxxxxxxx> > > A Landlock ruleset is mainly a red-black tree with Landlock rules as > nodes. This enables quick update and lookup to match a requested > access, e.g. to a file. A ruleset is usable through a dedicated file > descriptor (cf. following commit implementing syscalls) which enables a > process to create and populate a ruleset with new rules. > > A domain is a ruleset tied to a set of processes. This group of rules > defines the security policy enforced on these processes and their future > children. A domain can transition to a new domain which is the > intersection of all its constraints and those of a ruleset provided by > the current process. This modification only impact the current process. > This means that a process can only gain more constraints (i.e. lose > accesses) over time. > > Cc: James Morris <jmorris@xxxxxxxxx> > Cc: Jann Horn <jannh@xxxxxxxxxx> > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxxxxxxxxxx> > Acked-by: Serge Hallyn <serge@xxxxxxxxxx> > Link: https://lore.kernel.org/r/20210316204252.427806-3-mic@xxxxxxxxxxx (Aside: you appear to be self-adding your Link: tags -- AIUI, this is normally done by whoever pulls your series. I've only seen Link: tags added when needing to refer to something else not included in the series.) > [...] > +static void put_rule(struct landlock_rule *const rule) > +{ > + might_sleep(); > + if (!rule) > + return; > + landlock_put_object(rule->object); > + kfree(rule); > +} I'd expect this to be named "release" rather than "put" since it doesn't do any lifetime reference counting. > +static void build_check_ruleset(void) > +{ > + const struct landlock_ruleset ruleset = { > + .num_rules = ~0, > + .num_layers = ~0, > + }; > + > + BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); > + BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); > +} This is checking that the largest possible stored value is correctly within the LANDLOCK_MAX_* macro value? > [...] The locking all looks right, and given your test coverage and syzkaller work, it's hard for me to think of ways to prove it out any better. :) Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -- Kees Cook
